net: don't bind on 0.0.0.0 if binds are restricted to Tor

The semantic of `-bind` is to restrict the binding only to some address.
If not specified, then the user does not care and we bind to `0.0.0.0`.
If specified then we should honor the restriction and bind only to the
specified address.

Before this change, if no `-bind` is given then we would bind to
`0.0.0.0:8333` and to `127.0.0.1:8334` (incoming Tor) which is ok -
the user does not care to restrict the binding.

However, if only `-bind=addr:port=onion` is given (without ordinary
`-bind=`) then we would bind to `addr:port` _and_ to `0.0.0.0:8333` in
addition.

Change the above to not do the additional bind: if only
`-bind=addr:port=onion` is given (without ordinary `-bind=`) then bind
to `addr:port` (only) and consider incoming connections to that as Tor
and do not advertise it. I.e. a Tor-only node.

1 files changed, 21 insertions, 12 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 89e152e56f..e60ec093f2 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1721,18 +1721,6 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         return InitError(ResolveErrMsg("bind", bind_arg));
     }
 
-    if (connOptions.onion_binds.empty()) {
-        connOptions.onion_binds.push_back(DefaultOnionServiceTarget());
-    }
-
-    if (args.GetBoolArg("-listenonion", DEFAULT_LISTEN_ONION)) {
-        const auto bind_addr = connOptions.onion_binds.front();
-        if (connOptions.onion_binds.size() > 1) {
-            InitWarning(strprintf(_("More than one onion bind address is provided. Using %s for the automatically created Tor onion service."), bind_addr.ToStringIPPort()));
-        }
-        StartTorControl(bind_addr);
-    }
-
     for (const std::string& strBind : args.GetArgs("-whitebind")) {
         NetWhitebindPermissions whitebind;
         bilingual_str error;
@@ -1740,6 +1728,27 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         connOptions.vWhiteBinds.push_back(whitebind);
     }
 
+    // If the user did not specify -bind= or -whitebind= then we bind
+    // on any address - 0.0.0.0 (IPv4) and :: (IPv6).
+    connOptions.bind_on_any = args.GetArgs("-bind").empty() && args.GetArgs("-whitebind").empty();
+
+    CService onion_service_target;
+    if (!connOptions.onion_binds.empty()) {
+        onion_service_target = connOptions.onion_binds.front();
+    } else {
+        onion_service_target = DefaultOnionServiceTarget();
+        connOptions.onion_binds.push_back(onion_service_target);
+    }
+
+    if (args.GetBoolArg("-listenonion", DEFAULT_LISTEN_ONION)) {
+        if (connOptions.onion_binds.size() > 1) {
+            InitWarning(strprintf(_("More than one onion bind address is provided. Using %s "
+                                    "for the automatically created Tor onion service."),
+                                  onion_service_target.ToStringIPPort()));
+        }
+        StartTorControl(onion_service_target);
+    }
+
     for (const auto& net : args.GetArgs("-whitelist")) {
         NetWhitelistPermissions subnet;
         bilingual_str error;